1. Field of the Invention
The present invention relates to a toilet, and more particularly, to a drain valve base of a flush toilet.
2. Description of the Prior Art
A conventional drain valve of a water tank of a flush toilet comprises a valve plug, a driving assembly of a driving valve plug and a drain valve base. The drain valve base is a hollow configuration. As shown in FIG. 1 to FIG. 3, the drain valve base comprises an upper connection seat (10) and a lower connection seat (20) which are integrally formed. The upper connection seat (10) is connected with the lower connection seat (20) by connection arms (101) which are provided at intervals, and hollow portions (102) are formed between every two connection arms (101). The lower connection seat (20) has an annular surface (201) on a top end thereof. A through drain outlet (202) is formed in the center portion of the lower connection seat (20). The bottom of the lower connection seat (20) is connected to the drain hole at the bottom of the water tank. When the drain valve is closed, the valve plug of the drain valve is against a water-seal surface (201) to block water from flowing through a drain outlet (202). When the drain valve is opened, a driving member drives the valve plug to disengage from the water-seal surface (201). The water flows through the hollow portions (102) of the upper connection seat (10) to the drain outlet (202) to be discharged out of the water tank. The water flow generates a parabola path. Because the drain outlet (202) below the annular water-seal surface (201) is in a cylindrical shape, there is litter water at the inner wall of the drain outlet. The cross-sectional of the water flow is limited to the central portion of the drain outlet (202), so the drain speed of the water is low.
The drain speed of the water direct influences the function of the flush toilet. If the drain speed is low, the toilet cannot be flushed clean. Sometimes, it is necessary to flush the toilet many times, which wastes water.
Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.